[Svartmetall]

Like Horus before him, he was able to sway 3 complete Space Marine chapters to his cause.

Hmm. Not to rain on your theory but I would suggest that, in terms of persuasive ability, 9 Legions > 3 Chapters. I also got the feeling that Huron was being pushed a lot in the most recent Codex, but I don't think he could reasonably be seen as any kind of successor or threat to Abaddon; he's more of a 'supporting cast' kind of figure. Purely IMHO.